JP2638158B2 - Image forming device - Google Patents

Description

Description: BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an image forming apparatus, and more particularly to, for example, a method of arranging an exposure light source inside a photosensitive drum and developing toner simultaneously or immediately after exposure from the inside of the photosensitive drum. To an image forming apparatus.

(Prior art)

An example of this type of image forming apparatus is described in, for example,
This is disclosed in Japanese Patent Application Laid-Open No. 58-193957, which was published on March 13, 2013. In this image forming apparatus, the photoconductor layer is exposed from the transparent substrate side of the photoconductor including the transparent substrate and the transparent electrode layer and the photoconductor layer formed thereon,
The toner charged by the exposure is selectively adhered to the surface of the photoconductor layer at the same time as or immediately after the exposure by a developing device arranged on the photoconductor layer side to form a toner image.

In this image forming apparatus, when it is necessary to finely adjust the relative positional relationship between the irradiation position of the exposure light and the developing device, it is not clear in the above-mentioned Japanese Patent Application Laid-Open No. 58-193957,
An exposure light source, for example, an LED head, is moved in parallel so that the optical axis of the exposure light is slightly moved in a direction orthogonal to the optical axis.

[Problems to be solved by the invention]

In the above-described prior art, it was necessary to translate the LED head while operating both ends of the LED head. However,
When operating both ends of the LED head, not only is the operation troublesome, but also it is difficult to provide a fine adjustment mechanism at both ends due to the structure or the space.

In addition, if a large-diameter photosensitive drum is used, a recent small-diameter photosensitive drum can only fall within the focal depth of the exposure light by such a parallel movement depending on its curvature and the incident angle of the exposure light. Therefore, it is necessary to move the exposure light slightly in the optical axis direction.

Therefore, in the conventional apparatus, fine adjustment of the relative positional relationship between the irradiation position of the exposure light and the developing device has not been easy.

SUMMARY OF THE INVENTION Therefore, a main object of the present invention is to provide an image forming apparatus capable of easily finely adjusting a relative positional relationship between an irradiation position of exposure light and a developing device.

[Means for solving the problem]

In brief, the present invention provides a photoconductor including a transparent substrate and a transparent conductive layer and a photoconductor layer formed thereon and moved in a predetermined direction, a photoconductor arranged on the transparent substrate side of the photoconductor, and An exposure light source for exposing the photoconductor layer through the transparent substrate and the transparent conductive layer; and an exposure light source arranged at or near the exposure position of the exposure light source on the photoconductor layer side of the photoconductor, and simultaneously or immediately after the exposure. An image forming apparatus comprising: a developing unit configured to form a toner image by selectively adhering toner to a conductor surface, wherein an irradiation position of exposure light from an exposure light source is relatively displaceable with respect to the developing unit. An image forming apparatus comprising:

[Action]

The photoconductor is moved in a predetermined direction by driving means such as a driving roller, and such movement of the photoconductor is supported by a plurality of support rollers that come into contact with, for example, the transparent substrate side.

While the photoconductor is being moved, the photoconductor layer is irradiated with exposure light from an exposure light source such as an LED head through the transparent substrate and the transparent conductive layer. On the other hand, a DC voltage is applied between the developing means arranged at such an exposure position, for example, between the magnet roller and the transparent conductive layer. In the portion irradiated with the exposure light, the toner existing between the photoconductor layer and the magnet roller is changed by the current flowing between the magnet roller and the transparent conductive layer through the photoconductor layer whose resistance has been reduced by the exposure. The toner is not charged because the resistance of the photoconductor layer remains high in the charged and unirradiated portions. Therefore, the charged toner is adsorbed by the latent image charges of the photoconductor layer charged to the opposite polarity by the current. In this way, a toner image is formed on the photoconductor layer at the same time as or immediately after the exposure by the exposure light source.

As in the embodiment, when the photoconductor is formed as a drum, the light source for exposure is integrally provided in the photoconductor drum, and when the integrated object is supported by the support shafts on both sides in the width direction of the photoconductor drum, the support shaft is used for the light source. If the integrated object is rotated, the irradiation position of the exposure light from the exposure light source changes relative to the developing unit.

〔The invention's effect〕

According to the present invention, since the irradiation position of the exposure light from the exposure light source can be changed relatively to the developing means, fine adjustment of the relative positional relationship can be easily performed. At this time, if the unit of the photosensitive drum and the light source for exposure is rotated as in the embodiment, fine adjustment can be performed more easily.

The above and other objects, features and advantages of the present invention will become more apparent from the following detailed description of embodiments with reference to the drawings.

〔Example〕

FIG. 2 is an illustrative sectional view showing an optical printer as one embodiment of the present invention. Hereinafter, the present invention will be described as being applied to an optical printer, but it should be pointed out in advance that the present invention can be applied to other image forming apparatuses, such as a copying machine and a facsimile.

Referring to FIG. 2, the optical printer 10 includes a main body 12, and a photosensitive drum 14 is rotatably supported inside the main body 12.
As shown in FIG. 3, the photosensitive drum 14 is laminated on a transparent substrate 14a made of, for example, glass and the like, as in Japanese Patent Application Laid-Open No. 58-153957. It includes a transparent conductive layer 14b and a photoconductor layer 14c.

A drive roller 16 is provided so as to come into contact with the outer surface of the photoconductor drum 14 (the surface of the photoconductor layer 14c).
Reference numeral 16 rotates the photosensitive drum 14 by a driving force from a driving source such as a motor (not shown). The photosensitive drum 14
Since it is rotatably supported by two fixed support rollers 18 and 20 and one movable support roller 22 which are in contact with its inner surface, that is, the surface of the transparent base 14a, the drive roller 16
Is rotated in the direction of arrow A, the photosensitive drum 14 is accordingly rotated in the direction of arrow B. Although not apparent in the figure, the drive roller 16 is disposed at the widthwise end (preferably both ends) of the photoconductor drum 14, while the surface of the end of the photoconductor drum 14 that comes into contact with the drive roller 16 is slightly exposed. The photosensitive drum 14 is formed roughly, whereby the photosensitive drum 14 is accurately rotated by the friction between the two.

As described above, the photosensitive drum 14 is supported at three points by the fixed support rollers 18 and 20 and the movable support roller 22 on the inside thereof. As can be clearly seen from FIG.
These support rollers 18 to 22 are all disposed at both ends in the width direction of the photosensitive drum 14. And the movable support roller 22
Is preferably arranged at a center symmetrical position on a line connecting the center of the photosensitive drum 14 with the driving roller 16. That is, the movable support roller 22 is provided at a position facing the drive roller 16 with the rotation center of the photosensitive drum 14 interposed therebetween. The fixed support roller 18 is disposed on an extension of an exposure position of the photosensitive drum 14 described later.

Then, the mounting shafts 24 of the fixed support rollers 18 and 20 and
The reference numerals 26 are directly fixed to side plates 28 arranged at both ends of the photosensitive drum 14, respectively. On the other hand, the mounting shaft of the movable support roller 22
30 is not directly fixed to the side plate 28. That is, the mounting shaft 30 of the movable support roller 22 is attached to the side plates 28 on both sides so that the movable support roller 22 can apply a pressing force to the inside of the photosensitive drum 14 by the coil spring 32. Therefore, the movable support roller 22 can closely adhere to the photosensitive drum 14 in a state where the movable support roller 22 is always given a pressing force following the radial fluctuation of the inner circumference of the photosensitive drum 14. Therefore, the contact positions of the fixed support rollers 18 and 20 with the inner periphery of the photosensitive drum are constant even if the inner periphery of the photosensitive drum 14 is eccentric, but the contact positions of the movable support rollers 22 are within the photosensitive drum 14. It changes following the eccentricity of the circumference. Therefore, even when the diameter or roundness of the photosensitive drum 14 varies, such a dimensional variation can be absorbed by the displacement of the movable support roller 22.

In addition, as can be clearly seen from FIG.
The mounting shaft 26 of the movable support roller 22 and the mounting shaft 30 of the movable support roller 22 each have a length penetrating both ends in the width direction of the photosensitive drum 14, but the mounting shaft 24 of the fixed support roller 18 is short, It is approximately equal to the length of the roller 18. Then, each mounting shaft 24 is individually mounted on the side plates 28 at both ends. That is, an interval for exposing the photosensitive drum 14 to be described later is formed between the fixed support rollers 18.

Inside the photoconductor drum 14, an LED head 34 is further arranged. On one main surface of the LED head 34, a large number of L
An LED array 34a in which the ED elements are arranged on a straight line extending in the width direction of the photosensitive drum 14 is formed, and light from the LED array 34a is transmitted to a rod lens array fixed to the LED head 34 by an arm 36a. By the optical transmission body 36,
The photoconductor layer 14c is irradiated between the fixed support rollers 18 through the transparent base 14a and the transparent conductive layer 14b of the photoconductor drum 14.

By arranging the fixed support roller 18 on the optical axis of the exposure light in this way, the focus of the exposure light is reliably brought on the photoconductor layer 14c of the photosensitive drum 14. That is, at the position where the exposure light is irradiated, the photosensitive drum 14 is always maintained at a fixed position by the fixed support roller 18, and therefore, the position of the photoconductor layer 14c to which the exposure light is irradiated does not change. Therefore, if the focus of the exposure light is adjusted in advance to match the position, the exposure light will always be in the photoconductor layer.
Form an image on the 14c surface. Therefore, for example, even when the diameter or roundness of the photosensitive drum 14 varies, it does not affect the focus.

The LED head 34 is integrally fixed to the side plate 28 by screws 38 at both ends. Therefore, the relationship between the light irradiation position from the converging light transmitting body 36, that is, the exposure position, and the position where the fixed support roller 18 contacts the inner surface of the photosensitive drum 14 is always constant even when the photosensitive drum 14 rotates. . Therefore, if the focus of the converging light transmission body 36 is adjusted to match the surface of the photoconductor layer 14c of the photoconductor drum 14, the exposure light from there is always imaged on the surface of the photoconductor layer 14c. You. Therefore, for example, even when the photoconductor drum 14 is incorporated or detached, it is not necessary to make the focus position of the converging light transmission body 36 coincide with the surface of the photoconductor layer 14c.

Returning to FIG. 2, the main body 12 is provided with a developing device 40 on the left side of the photosensitive drum 14. The developing device 40 is attached to the chassis of the main body 12 by a coil spring 42 so as to be always engaged with the photosensitive drum 14. The developing device 40 is loaded with a toner cartridge 44, and the toner supplied from the toner cartridge 44 into the developer chamber 46 is transported to the magnet roller 50 by the transport screw 48. The transported toner is formed as a magnetic brush on the circumference of the magnet roller 50. Then, the height of the magnetic brush, that is, the height of the spike is adjusted by the spike restricting plate 52, and is transferred to a portion facing the photosensitive drum 14 according to the rotation of the magnet roller 50. That is, the toner is sent between the magnet roller 50 and the photoconductor layer 14c of the photosensitive drum 14.

On the other hand, although not shown, a DC voltage of, for example, 200 V is applied between the magnet roller 50 and the transparent conductive layer 14b of the photosensitive drum 14. The photoconductive layer 14c of the photosensitive drum 14 facing the magnet roller 50 has the LED
Exposure light according to image information is emitted by the head 34 and the converging light transmitting body 36. In the portion of the photoconductor layer 14c that has received the exposure light, the resistance value is reduced, and therefore, a current flows between the magnet roller 50 and the transparent conductive layer 14b due to the above-described voltage. Therefore, the toner present in that portion is charged by the current. On the other hand, in the part which is not exposed, the resistance of the photoconductor layer remains high and no current flows, so that the toner is hardly charged. On the exposed photoconductor drum 14, that is, on the photoconductor layer 14c, a latent image charge having a polarity opposite to the charge polarity of the toner is generated by the above-described current. It is adsorbed on the surface of the body layer 14c by electrostatic force. Thus, almost simultaneously with the exposure by the LED head 34,
The developing device 40 forms a toner image on the photosensitive drum 14.

In order to perform good toner development, it is necessary not only to accurately set the interval between the above-described portions where the magnet roller 50 and the photosensitive drum 14 face each other, but also to set the portions with respect to the optical axis of the exposure light. The magnet roller 50 and the photosensitive drum 14 need to be positioned so as to be orthogonal to each other exactly. Therefore, in this embodiment, the above-described positioning of this portion is set by two positioning members 54 arranged at both ends in the width direction of the intermediate drum 14 and parallel to each other as shown in FIG. On the other hand, the above-mentioned gap is rotatable at both ends of the magnet roller 50 as shown in FIG.
51 may be provided, and the gap roller 51 may be defined by contacting the surface of the photosensitive drum 14 with the gap roller 51. At the left end of each positioning member 54, a semicircular fitting portion 58 to which the mounting shaft 56 of the magnet roller 50 is fitted is formed.

On the other hand, as described above, the LED head 34 and the like are integrally fixed.
Support shafts 60 and 62 are formed on the side plates 28 for setting a gap with the magnet roller 50 by the positioning member 54, respectively. As can be clearly seen from FIG.
The support shaft 60 is fixed substantially at the center of the disk-shaped side plate 28,
62 is fixed near the end of the side plate 28. Each positioning member 54 has a substantially L-shaped fitting portion 64 for fitting the support shafts 60 and 62 at the same time. In addition, a rotating grip portion 66 is formed integrally with one of the side plates 28, that is, the front side plate 28 in FIG.

And the positioning member already attached to the main body 12
By fitting the support shafts 60 and 62 into the fitting portions 64 of the photosensitive drum 14, the photosensitive drum 14 and an integral part thereof are attached to the main body 12. At this time, since the entrance of the fitting portion 64 is narrow, the support shafts 60 and 62 cannot be fitted into the fitting portion 64 at the same time. Therefore, first, the support shaft 60 is fitted into the fitting portion 64, and when the support shafts 60 on both sides are fitted into the fitting portion 64, the photosensitive drum 14 is axis
62 is also fitted into the fitting portion 64. Thus, the support shaft 60
When (and 62) are fitted into the fitting portion 64, the magnet roller 50 and the photoconductor layer 14c of the photosensitive drum 14 are positioned so that the portion where the photoconductor layer 14c faces is orthogonal to the optical axis of the exposure light. You. The gap between the magnet roller 50 and the photosensitive drum 14 is set optimally by setting the diameter of the gap roller 51 optimally.

However, merely fitting the support shafts 60 and 62 into the fitting portion 64 as described above,
Is not always exactly perpendicular to the optical axis of the exposure light. In such a case, after the support shafts 60 and 62 are fitted into the fitting portion 64, the photosensitive drum 14 is rotated about the support shaft 60 as shown in FIG. What is necessary is just to slightly rotate the moving holding part 66. At this time, the support shaft 62 slides on the fitting portion 64 and serves as a guide for its rotation. Then, the rotating grip 66 is rotated so that the projection 68 formed on the rotating grip 66 coincides with the center of the scale 72 provided on the chassis 70 of the main body 12. Protrusion 68 and scale
If the center of 72 is coincident, the magnet roller 50 and the photosensitive drum 14
The parts facing each other are exactly orthogonal.

In this way, when finely adjusting the relative positional relationship between the current position by the magnet roller 50 and the irradiation position of the exposure light, the photoreceptor is simply rotated by the rotation gripper 66 about the support shaft 60. The position of the LED head 34 provided in the drum 14, that is, the position of the converging light transmitting body 36 can be easily adjusted.

The side plate 28 is fixed to the chassis 70 in a state where the exposure position is located at a position facing the magnet roller 50 as described above. That is, a long elliptical hole 74 for integrally fixing the one side plate 28 to the chassis 70 is formed in the rotary holding portion 66. Therefore, the side plate 28 may be integrally fixed to the chassis 70 with the screw 76 through the hole 74 when the protrusion 68 and the scale 72 match.

As shown in FIG. 2, in the main body 12, a paper feed cassette 78 is removably mounted obliquely above the developing device 40. A large number of recording papers 80 are stacked and stored in the paper supply cassette 78, and the recording papers 80 are arranged on a plate 82.
Since the plate 82 is pushed up by the coil spring 84, the uppermost recording paper 80 stacked is pressed against the paper feed roller 86. Therefore, when the paper feed roller 86 is driven, the paper 80 is sent to a pair of register rollers including a drive roller 88 and a driven roller 90.

Near the upper part of the photosensitive drum 14, specifically, a fixed support roller
A transfer roller 92 having a length in the width direction substantially equal to that of the photosensitive drum 14 is provided at a position facing the photosensitive drum 14. Drive roller
The toner image formed as described above is transferred onto the surface of the photosensitive drum 14 by the transfer roller 92 on the recording paper 80 which is sent in a timing-controlled manner by a pair of register rollers 88 and a driven roller 90. .

The recording paper 80 after the transfer is peeled off from the photosensitive drum 14 by the separating claw 96. Then, the recording paper 80 is fixed by the heating roller 100 and the pressure roller 102 while the suction fan 98 applies a slightly upward suction force so that the unfixed toner image on the recording paper 80 is not disturbed. Conveyed to the device.

Inside the heating roller 100, for example, a halogen lamp of about 850 W is built in, and a part of the surface is pressed against a felt 104 impregnated with silicone oil. Therefore,
When the recording paper 80 passes between the heating roller 100 and the pressure roller 102, the toner image is heated and pressed, and the fixing process ends. Then, the recording paper 80 is peeled off from the surface of the heating roller 100 by the separation claw 106, conveyed to a pair of paper discharge rollers including paper discharge rollers 108 and 110, and discharged out of the main body 12.

A cleaning blade 112 is attached below the separation claw 96 and near the peripheral side surface of the photosensitive drum 14 so that a part thereof comes into contact with the surface of the photosensitive drum 14. The cleaning blade 112 is made of rubber, and scrapes residual toner by contacting the surface of the photosensitive drum 14. The scraped residual toner is stored in a waste toner container 114 below. This waste toner container 114 is also removably loaded into the main body 12 similarly to the developing cartridge 44 described above. Therefore, when the waste toner is full, the waste toner container 114 is replaced with an empty one.

In this embodiment, a part of the main body 12 is configured as an openable separation unit 116 so that the jammed recording paper 80 can be easily removed. This separation unit 116
Includes a driven roller 90, a pressure roller 102, a paper discharge roller 110, and a transfer roller 92, which constitute a register roller pair, a fixing roller pair, and a paper discharge roller pair. The separation unit 116 is mounted on the main body 12 so as to be openable upward about the support shaft 118 as a rotation center. Therefore, for example, when a jam occurs, the separation unit 11
When 6 is opened upward around the support shaft 118, the recording paper transport path is exposed. As a result, the jammed recording paper 80
Can be easily removed from the recording paper transport path.

The photosensitive drum 14 is detached from the main body 12 in the following procedure, for example, when it becomes necessary to inspect the surface of the photosensitive drum 14. First, the separation unit 116 is rotated upward about the support shaft 118 to separate the transfer roller 92 from the surface of the photosensitive drum 14. As a result, a work space is formed above the photosensitive drum 14 in a portion where the transfer roller 92 was disposed.
Next, the screw 76 as shown in FIG. 4 is loosened and removed. Then, the rotating holding portion 66 is moved to the fitting portion 64 of the positioning member 54.
Then, it becomes rotatable about the support shaft 60 fitted to the shaft. Therefore, the rotating grip 66 is slightly rotated upward,
The support shaft 62 is slightly lifted from the bottom of the fitting portion 64, and the support shaft 62 is guided to the outlet of the fitting portion 64. Then, after both support shafts 60 can be disengaged from the fitting portion 64, when the rotating holding portion 66 is lifted and the entire photosensitive drum 14 is pulled out along with the side plate 28 in the horizontal direction, the photosensitive drum 14 and the integral with the photosensitive drum 14 are extracted. Things fall out of 12 almost entirely.

Attachment of the photosensitive drum 14 to the main body 12 is performed in a procedure reverse to that when the photosensitive drum 14 is removed from the main body 12. At this time, the gap between the magnet roller 50 and the exposure position of the photosensitive drum 14 is determined by the diameter of the gap roller 51.
The gap between the magnet roller 50 and the exposure position is automatically set simply by mounting the photosensitive drum 14 on the photosensitive drum 12. Then, at this time, the relative position between the magnet roller 50 and the photosensitive drum 14 is adjusted by the rotating gripping part 66 as necessary.

In the above-described embodiment, the photosensitive drum 14 is rotated by the driving roller 16 which contacts the outside. However, the photosensitive drum 14 may be driven directly by a motor, for example, or may be driven via another driving means such as a combination of a timing pulley and a timing belt or a gear train.

[Brief description of the drawings]

FIG. 1 is an exploded perspective view showing a fitted state of a photosensitive drum, a positioning member and a magnet roller in an optical printer as one embodiment of the present invention. FIG. 2 is an illustrative sectional view showing the entire optical printer of this embodiment. FIG. 3 is an enlarged fragmentary sectional view showing an example of a photosensitive drum that can be used in this embodiment. FIG. 4 is a side view showing the fitting state of the photosensitive drum, the positioning member and the magnet roller in the optical printer of this embodiment. In the figure, 10 is an optical printer, 12 is a main body, 14 is a photosensitive drum, 16 is a drive roller, 18 and 20 are fixed support rollers, 22 is a movable support roller, 28 is a side plate, 34 is an LED head, and 36 is a focusing property. Optical transmission body, 40 is a developing device, 50 is a magnet roller, 51
Is a gap roller, 54 is a positioning member, 56 is a mounting shaft, 5
Reference numerals 8 and 64 denote fitting parts, reference numerals 60 and 62 denote support shafts, and reference numeral 66 denotes a rotary gripping part.

 ────────────────────────────────────────────────── ─── Continuing on the front page (72) Inventor Toshiyuki Hoshino 1-1-6 Uchisaiwaicho, Chiyoda-ku, Tokyo Nippon Telegraph and Telephone Corporation (72) Inventor Shinji Tetsuya 1-16-1 Uchisaiwaicho, Chiyoda-ku, Tokyo No. Nippon Telegraph and Telephone Corporation (72) Inventor Masaru Ozawa 1-1-6 Uchisaiwaicho, Chiyoda-ku, Tokyo Nippon Telegraph and Telephone Corporation

Claims (7)

(57) [Claims] 1. A photoreceptor which includes a transparent substrate and a transparent conductive layer and a photoconductor layer formed thereon and is moved in a predetermined direction, a transparent substrate and a transparent substrate which are disposed on the transparent substrate side of the photoreceptor. An exposure light source for exposing the photoconductor layer through the conductive layer; and an exposure light source on the photoconductor layer side of the photoreceptor, which is disposed at or near the exposure position by the exposure light source and simultaneously or immediately after exposure on the photoconductor surface. An image forming apparatus comprising: a developing unit that selectively adheres toner to form a toner image, wherein an irradiation position of the exposure light by the exposure light source can be relatively changed with respect to the developing unit. An image forming apparatus. 2. The image forming apparatus according to claim 1, wherein the photoconductor is formed as a hollow cylindrical drum having the photoconductor layer on the outer surface. 3. The exposure light source according to claim 1, wherein the exposure light source is provided integrally with the photoconductor drum in the photoconductor drum, and has a displacement mechanism for displacing the photoconductor drum to achieve a change in the irradiation position of the exposure light. The image forming apparatus according to claim 2, further comprising: 4. A means for supporting an integral body of the photosensitive drum and the light source for exposure on both sides in the width direction of the photosensitive drum, wherein the displacement mechanism rotates the integral body by the support shaft. The image forming apparatus according to claim 3, further comprising: 5. The image forming apparatus according to claim 4, further comprising a rotation confirmation unit for confirming a state of rotation of said integrated object. 6. An image forming apparatus according to claim 6, wherein said rotation confirming means includes an instruction section displaced together with said integrated object and a scale indicated by said instruction section. 7. A displacement mechanism comprising: a plurality of support rollers for contacting an inner periphery of the photoconductor drum and supporting movement in a predetermined direction, and provided integrally with the photoconductor drum; The image forming apparatus according to claim 3, wherein an integrated body of the photosensitive drum, the exposure light source, and the plurality of support rollers is displaced.